The present invention relates to an automatic developing apparatus used for continuously processing silver halide photosensitive material. More particularly, the present invention relates to a compact automatic developing apparatus in which dissolution work of the solid processing agent is avoided so that the workability can be greatly improved and further excellent photographic characteristics can be stably provided. Further, the present invention relates to an improvement in the replenishment mechanism for replenishing a solid processing agent by which deterioration of the solid processing agent can be prevented and a stable replenishment operation can be carried out.
In general, the processing agent is replenished to an automatic developing apparatus in the following manner: A processing agent kit containing one type or several types of concentrated solutions is previously mixed with and dissolved in water. The thus prepared replenishing solution is stocked in a replenishing tank. In accordance with the throughput of photosensitive material, a small amount of replenishing solution is automatically replenished to the processing tank. In this case, it is necessary to provide replenishing solution tanks, the number of which is the same as that of the types of the processing solutions. In general, the above dissolving work is manually carried out by operators. Accordingly, there is a possibility that mistakes are made in the dissolving procedure, for example, mistakes tend to be made in the type of the processing solution, the amount of dissolving water, and the order of dissolution. Since the processing agent kit contains concentrated chemicals, it is necessary to treat them carefully. For this reason, operators of the automatic developing apparatus have long desired to be released from the dissolving work of replenishing solutions. In order to meet the requirements, several methods are employed, for example, commodities are supplied in the form of a previously prepared replenishing solution, or plural types of concentrated solutions are automatically supplied. However, the aforementioned methods are disadvantageous as described below. According to the former method, the device is more bulky than the kit of concentrated solutions. According to the latter method, it is necessary to provide a complicated device, which is not suitable for a compact automatic developing apparatus called a mini-laboratory. Also, the replenishing solution tank occupies a large space. Therefore, it is difficult to make the automatic developing apparatus to be compact.
In order to meet the demands described above, Japanese Patent Publication Open to Public Inspection No. 119454/1993 discloses a method in which almost all processing agent components are made to be in the forms of solid processing agents, which are directly charged into the processing tank. According to this method, it is not necessary to prepare the replenishing solution, and in accordance with the throughput of photosensitive material, the solid processing agent is directly charged into the processing solution in the automatic developing apparatus by the automatic replenishing device. In this way, the solid processing agent is dissolved. In this case, the solid processing agent is previously stocked in an accommodating section, and a necessary amount of solid processing agent is taken out from there by the automatic replenishing device and charged into the processing solution. However, when the solid processing agent drops onto the solution surface, the solution splashes and scatters, and further vapor generated from the solution surface affects the solid processing agent. These are problems peculiar to the solid processing agent.
Problems are specifically described as follows. Most of the components of the solid processing agent are hygroscopic chemicals. Accordingly, when the solid processing agent absorbs moisture or gets wet with a splash of the solution, the components of the solid processing agent are deteriorated, and further blocks of the solid processing agent stick to each other, that is, the phenomenon of blocking is caused. Furthermore, the processing agent is expanded, and the dimensions are changed and the mechanical strength is lowered. In this way, the performance of the solid processing agent is deteriorated. Due to the foregoing, the sliding property of the solid processing agent is deteriorated, which causes a breakdown of the replenishing device. Unless the processing agent is positively charged into the processing solution, the composition of the solid processing solution can not be appropriately maintained, which could result in a serious problem.
Accordingly, it is most important to prevent the solid processing agent from coming into contact with moisture and humidity. In order to accomplish the above object, various investigations have been made until now.
Japanese Patent Publication Open to Public Inspection No. 107715/1993 discloses a method in which a rotatable floating cover is provided on a solution surface onto which the solid processing agent is charged, wherein the rotational shaft of the floating cover is set on the solution surface. Japanese Patent Publication Open to Public Inspection No. 107715/1993 also discloses a method in which floating globes are arranged on the solution surface. However, this method is disadvantageous in that the processing agent components are deposited on the members when the frequency of charging the solid processing agent is extremely lowered, and operation can not be accurately effected.
Japanese Patent Publication Open to Public Inspection No. 107714/1993 discloses a method in which the solid processing agent is charged into the solution by the replenishing device from a position not opposed to the solution surface. This method is advantageous in that the solid processing agent or the replenishing device is not directly splashed with the solution so that the solid processing agent is not wet with the solution. However, even the outside of the wall of the dissolution tank is splashed, and other processing tanks are stained with the splashed solution. Therefore, it is difficult to perfectly prevent the contamination of other portions of the automatic developing apparatus.
Japanese Patent Publication Open to Public Inspection No. 107713/1993 discloses a method in which the solid processing agent is sent from the replenishing device to an inclined chute and the solid processing agent is slid on the chute to the surface of the solution. According to this method, the dropping speed of the solid processing agent is reduced, and an amount of splash of the solution can be reduced to the minimum. This method is very effective to reduce the splash and moisture given to the solid processing agent.
However, when the dimensions of the dissolution tank are reduced so as to make the automatic developing apparatus compact, an allowable range of the splash zone becomes very small and severe. Therefore, it is difficult to solve the problems by the above method.
The problems will be described in detail as follows. When the dimensions of the dissolution tank are reduced, the splashed solution is deposited on the wall of the dissolution tank. When the processing is continued over a long period of time, an amount of the deposited solution on the wall is gradually increased. In the worst case, the processing solution is sucked upward in the deposited solid component by the capillary action, and the deposited solid component grows upward and finally reaches the outside of the dissolution tank, which causes corrosion of the important parts of the automatic developing apparatus. Due to the corrosion, troubles of the apparatus develop. A mist-like solution tends to splash into other processing solution tank. Accordingly, it is necessary to greatly reduce an amount of splashed solution.
In order to reduce the amount of splashed solution, it is effective to lower the lowermost end portion of the inclined surface, on which the solid processing agent slid, to a position close to the solution surface. However, when the lowermost end portion of the inclined surface is lowered, the inclined surface of the chute gets wet with the splashed solution. When the chute is covered with a tube-shaped member to prevent the chute from getting wet, steam gets into the chute from the solution surface, and dew condensation is caused in the solid processing agent replenishing device. Further, the inside of the chute is subjected to dew condensation, so that the inclined surface on which the solid processing agent passes gets wet. In the process of replenishing operation, the solid processing agent comes into contact with the wet portion of the inclined surface, and the solid processing agent is deposited on the surface, which causes problems, and further the movable portions of the replenishing device can not be driven smoothly, and in the worst case, the chute gets clogged by the deposited solid processing agent.
Another method for reducing the splash of the solution is to reduce an angle of the inclined chute. This method is effective to lower the sliding speed of the solid processing agent on the chute. However, this method is disadvantageous, because there is a possibility that the solid processing agent is caught on the inclined chute surface and the reliability is lowered.